To develop an effective T cell-based immunotherapy against HIV-1, one confronts three complicating factors: 1) an extreme sequence diversity among HIV-1 strains; 2) polymorphism of HLA among human population; and 3) the very cells required to mount effective immune responses are infected by viruses. To overcome these factors, we have fused a single chain Fv (scFv) of human monoclonal antibody to transmembrane and signal transduction domains of two subunits of type I interferon receptors IFNAR1 and IFNAR2L. The high affinity antibody recognizes a conserved epitope in HIV-1 gp41. We hypothesized that by expressing chimeric receptors on the surface of T cells, they will recognize gp41 on the surface of viral particles or HIV-1-infected cells and trigger the JAK/STAT/IRF signal transduction pathway. As a result, transduced CD4 T cells will become resistant to and CD8 T cells will mount a vigorous response against HIV-1. In the preliminary studies, the genes encoding chimeric receptors and EGFP control were transduced into chronically HIV-1-infected ACH-2 cells and properly expressed. Expression of chimeric receptors does not alter cell growth and CD4 and CXCR4 expression. However, HIV-1 release and spread are substantially inhibited in cells transduced with both scFv-IFNAR1 (SR1) and scFv-IFNAR2L (SR2L) or with SR2L alone. HIV-1 spread, but not release, in cells transduced with SR1 alone is also inhibited to a lesser degree. In this proposal, we will first characterize the mechanisms of HIV-1 inhibition of chimeric receptors in chronically HW-1-infected cells. We will determine if chimeric receptors can bind to gp41 on the surface of viral particles and trigger the JAK/STAT/IRF signal transduction pathway and if so, whether the signal transduction pathway triggered by chimeric receptors is a prerequisite for their inhibition of HIV-1. Second, we will study anti-HIV-1 activity of chimeric receptors in primary human CD4 and CD8 T cells. We will transduce the genes encoding chimeric receptors and EGFP into primary human CD4 and CD8 T cells. The transduced CD4 T cells will be challenged with primary HW-1 isolates to test if expression of chimeric receptors renders them resistant to acute HW- 1 infection. If so, we will determine at what step(s) of the viral cycle inhibition takes place. We will test if expression of chimeric receptors in transduced CD8 Tcells will enable them to effectively recognize and kill or inhibit viral replication in H1V-1-infected cells through cytolytic and non-cytolytic means. If successful, this strategy will have broad applications in immunotherapy and immune reconstitution against HIV-1.